Different ways of loading JavaScript source

In addition to just evaluating strings, you can also use streams, such
as files.

evaluate bytes read from any File/IO object:

File.open("mysource.js") do |file|
cxt.eval(file, "mysource.js")
end

or load it by filename

cxt.load("mysource.js")

Safe by default, dangerous by demand

The Ruby Racer is designed to let you evaluate JavaScript as safely as
possible unless you tell it to do something more dangerous. The
default context is a hermetically sealed JavaScript environment with
only the standard JavaScript objects and functions. Nothing from the
Ruby world is accessible at all.

For Ruby objects that you explicitly embed into JavaScript, by default
only the public methods belowObject are exposed by default.
E.g.

Protecting Your CPU cycles

When running untrusted JavaScript code, you not only have to protect
which functions it has access to, but also how much of your CPU it can
consume. Take this simple, yet thoroughly malicious script:

while (true) {}

It will loop forever and never return control to the calling Ruby
thread. To protect against such JavaScript code that either
deliberately or accidentally runs longer that it should, you can
set an explicit timeout on your context. If the code runs longer that
the allowed timeout, then it will throw an exception. Note that this
exception could be raised at any point in the execution of the
JavaScript.

To specify the timeout (in milliseconds), pass in the timeout option
to the constructor.

PREREQUISITES

The Ruby Racer requires the V8 Javascript engine, but it offloads the
handling of this dependency to the
libv8 gem. Because libv8 is now a
gem dependency, you do not need a separate libv8 entry in your
project's Gemfile.

DEVELOP

Sponsored by

LICENSE:

(The MIT License)

Copyright (c) 2009,2010,2011,2012 Charles Lowell

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.